Method for packaging perishable foods and other articles, and package therefor

ABSTRACT

Method of packaging a perishable item wherein the perishable item is put into a liquid and gas tight container having an opening located above the perishable item, and the container opening is sealed with a liquid tight film of material permeable to gases with the film containing ingredients that will produce CO 2  and ClO 2  when contacted by moisture vapor. A package made of a liquid and gas tight container having an opening located in an upper portion, a perishable item located in the container below the opening, and a liquid tight film of material permeable to gases sealing said opening with the film containing ingredients that will produce CO 2  and ClO 2  when contacted by moisture vapor.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a method for packaging perishable foods and other articles and especially to a method for packaging fresh fish and seafood and to a novel package, particularly for fresh fish and seafood. More particularly the present invention relates to a method for packaging perishable items using s modified atmosphere packaging of gases from lidding material, that is, materials used for forming lids that can be hermetically heat sealed to plastic containers. The invention also relates to a novel food tray or bag that will create in a food package a modified gas atmosphere.

[0003] 2. Prior Art

[0004] Existing, conventional, modified atmosphere packaging is flushed with CO₂ gas. While this addresses the aerobic bacteria, it does not address anaerobic bacteria that can cause illnesses such as botulism. Up to the present, it has not been possible to sell packaged fresh fish and/or seafood in supermarkets and other retail outlets, because of the presence of both aerobic and anaerobic bacteria that can cause a number of serious illnesses, including botulism. Therefore, all fresh fish and seafood is currently sold on ice, non-packaged. All other fish and seafood is sold only in a frozen condition.

[0005] In addition, other foods and articles, such as, meat, poultry, seafood, produce including fruits and vegetables, and flowers, to name a few, degrade in a relatively short period of time.

SUMMARY OF THE INVENTION

[0006] The principal object of the present invention is to provide a method for packaging perishable foods and other articles, and in particular, to a method for packaging fresh fish and seafood in a modified and controlled atmosphere, and to a novel package therefor.

[0007] According to the present invention there is provided a method of packaging a perishable item comprising the steps of placing the perishable item in a liquid and/or gas tight container having an opening located above the perishable item, and sealing the container opening with a liquid tight film of material permeable to gases with the film containing ingredients that will produce CO₂ and ClO₂ when contacted by moisture vapor. In the methods described, the film material can constitute a laminate of a top film, a bottom film and a layer of adhesive binding said films together, with the gas generating ingredients being dispersed in the adhesive. Further, the top film can be characterized as having (1) a high moisture vapor transmission rate and (2) a low gas transmission rate and the bottom film can be characterized by having (1) a low moisture vapor transmission rate and (2) a high gas transmission rate. Alternatively, the film can comprise only two layers, a first one that is a gas tight barrier layer and a second one that is a layer containing the gas generating ingredients. The second layer is heat scalable either to close a container, or to form the container, i.e., bag, itself; such a construction is useful where the product in the container has sufficient moisture in it. Further, a single layer that contains the gas generating ingredients can be coated on the inside of a tray or on a pad in a tray or bag.

[0008] In a further development of the invention, a package is provided comprising, a liquid and gas tight container having an opening located in an upper portion, a perishable item located in the container below the opening, and a liquid tight film of material permeable to gases sealing said opening with the film containing ingredients that will produce CO₂ and ClO₂ when contacted by moisture vapor. The novel package of the invention can be formulated so that the film material constitutes a laminate of a top gas tight barrier layer, and a bottom layer that is heat scalable to the rim of a tray or to form its own container, e.g. a bag, with the gas generating ingredients being dispersed in the bottom layer. Further, the novel package can be arranged so that the top film is characterized as having no transmission to liquids and gases, i.e., a barrier layer, and the bottom film is characterized by having (1) a good moisture vapor transmission rate and (2) a high gas transmission rate.

[0009] As noted above, fresh seafood is subject to the formation of aerobic and anaerobic bacteria. The novel modified atmosphere packaging system according to the present invention contains a flexible lidding (plastic film) material which releases gases, such as, carbon dioxide and chlorine dioxide, thereby addressing both the aerobic and anaerobic (illness forming and product degrading) bacteria and viruses. The novel package of the present invention provides a modified atmosphere package allowing healthier, more convenient seafood (case ready), which enjoys improved presentation and extended shelf life.

[0010] As noted above, the present invention utilizes the lidding materials employed to seal the tops of containers, like food trays. Lidding materials are typically comprised of several materials that are combined either through coextrusion and/or lamination. The bottom layer of a lidding material is a heat scalable material that is pressed against the top lip of the tray with heat to form a bond between the two surfaces.

[0011] According to the present invention, the preferred lidding material (containing a barrier layer or not depending on use) is a heat scalable material that is a polymer, such as a linear low-density polyethylene (LLDPE), into which has been blended in powder or particulate form chemicals capable of releasing gases (such as, both carbon dioxide and chlorine dioxide) when water vapor, passing through the film or present in the package, contacts the heat scalable layer of the lidding material. The powdered gas producing material could also be dispersed in an adhesive used to bond the heat scalable material to the next upper layer in the lidding structure. Further, the powdered gas producing material can be formulated, compounded, dispersed in, interspersed or impregnated in any layer or interstitial part of the lidding material. Also, the lidding material structure can contain a liquid-gas barrier layer above the portion of the lidding material carrying the powdered gas producing material, so long as the powdered gas producing material is exposed to the package interior via gas permeability of the lidding material structure between the location of the powdered gas generating material and the package interior.

[0012] The invention is accomplished by packaging the food or other perishable article in a modified and controlled atmosphere, as is evident from the foregoing. A better understanding of the nature and scope of the present invention can be gained by considering, for example, the packaging of fresh fish. For example, fresh fish is inserted or placed in a gaslight container, such as a tray having an open top that presents a peripheral rim. A special laminated film structure is sealed around the top rim of the opening at the top of the tray. The seal is a hermetic seal. The fresh fish is positioned in the bottom of the container or tray prior to sealing the laminated film structure. The interior chamber of the tray and the fresh fish are subject to a modified and controlled atmosphere by passage of gases through the laminated film structure. The laminated film is constructed of a top sheet or film that is liquid tight and permeable to moisture vapor and other gases, but is especially characterized to have a high transmission rate to moisture vapor and a low transmission rate for other gases. The bottom sheet or film is liquid tight and permeable to moisture vapor and other gases, but is characterized to have a high transmission rate for other gases and a low transmission rate for moisture vapor. The two sheets or films are laminated together with a suitable adhesive, in a known manner. The adhesive, however, according to the present invention has dispersed therein particles of a first chemical substance that generates CO₂ when subjected to moisture, and a second chemical substance that generates ClO₂ gas when subjected to moisture. The chemicals that will so react to moisture to evolve the mentioned gases are well known in the art.

[0013] The advantages of the invention are simplicity, cost savings and convenience.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Other objects and advantages will become readily apparent from the following detailed description of the invention when taken in conjunction with the appended drawings in which:

[0015]FIG. 1 is a side view of a tray containing fresh fish that was made according to the present invention; and

[0016]FIG. 2 is a section through the lamination sealed across the top of the tray containing fresh fish depicted in FIG. 1.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0017] The invention will now be described with reference to the accompanying figures of the drawing with respect to preferred embodiments.

[0018] Referring to the figures of the drawing, FIG. 1 shows a standard plastic tray 10 that is both liquid tight and gas tight, as currently being used for packaging meat, poultry or the like. The tray is molded from suitable plastic material with a shallow cup shape or central depression to receive an article of food. As shown in FIG. 1, a fish product, designated by the reference numeral 12, is loaded or positioned in the bottom of the tray. Whereas only one item of food is shown in the tray, the contents of the tray will depend on the nature of the food and the number of pieces of each food item that are desirable to place in the tray. The amount of the contents of the tray is incidental to the present invention. The tray 10 has an open top defined by a reversely curved rim 14 as is common practice. The open top of the tray is seal by a special laminated film structure 16, which will be described herein in greater detail, that is hermetically sealed to the rim to close and seal the open top of the tray to complete a fully enclosed package.

[0019] The special laminated film structure 16 is shown in cross section in FIG. 2, and consists of a top film laminate 20 that is characterized by having (1) a high moisture vapor transmission rate and (2) a low gas transmission rate; a bottom film laminate 22 that is characterized by having (1) a low moisture vapor transmission rate and (2) a high gas transmission rate; and adhesive 24 for lamination of the films 20 and 22 the contains (1) a moisture activated ingredient which creates CO₂ gas and (2) a moisture activated ingredient which creates ClO₂ gas. The films 20 and 22 are made of plastic and their composition and construction are known in the art. Also, the adhesives that are useful for laminating plastic films are well known in the art. Further, the ingredients, constituents, or chemicals that can generate CO₂ or ClO₂ gases are well known in the art, as well, as the nature and character of the particles that can be dispersed in the known adhesives. Since such is known to those skilled in the art, therefore, there is no need to explain or elaborate on such known materials or their properties and characteristics.

[0020] With the package made by the method described, the package is case-ready, and provides a modified atmosphere packaging for fresh seafood. Moisture/humidity passes through the top film laminate 20, see arrow marked A, and activates the CO₂ and ClO₂ ingredients in the adhesive 24 generating or creating CO₂ and ClO₂ gases which, being heavier than air, pass down through the bottom film laminate 22, see arrow B, and form a gaseous shroud or cloud 26 around the fish or seafood 12. This gas shroud or cloud 26 forms an modified atmosphere in the package that kills bacteria (aerobic and anaerobic) and viruses.

[0021] In another embodiment, the film 16 is composed of two layers, a top layer of barrier material, and a bottom layer containing the gas generating ingredients. Such an embodiment is useful for food and other items that contain sufficient moisture, and do not need for moisture to penetrate into the package to generate the gases. Such a film (including a barrier layer or not depending on use) can be fabricated into and used directly as a bag or pouch. Also, the film of this embodiment can be used as a liner for a tray or on a pad in a tray. In still another embodiment, a moisture permeable coating or layer containing the gas generating ingredients can be coated on, attached or integrated directly on the tray, or pad used in the tray. In a still further embodiment, a film containing the gas generating ingredients, structured as a monolayer, as a series of overlaying laminations with or without adhesives or binders, with or without a barrier layer depending on use and the presence of moisture in the packaged item, can be made as a patch, or a patch can be made of plastic film containing a barrier layer and having an adhesive on one face containing the gas generating ingredients. The adhesive may be covered with a strippable protective covering that is remove just before use when the patch, adhesive side exposed, is stuck or applied to the object that is to be treated with the gases. The plastic forming the patch may not have a barrier layer, if it is desired to have moisture penetrate through the patch to activate the adhesive containing the gas generating ingredients.

[0022] In a further development of the invention, a permeable plastic film of substantial thickness having dispersed therein the gas generating ingredients may be made as an independent free standing structure, like a pad, and inserted in a package. The film can be perforated to increase the contact between the moisture and the gas generating ingredients. Also, the pad can contain a means, like an adhesive, so it can be applied to a part of the interior of the package or its contents, or the film can be tacked by heat sealing to an appropriate portion of the interior of the package. If tacked only at spaced locations, such as the four corners, or at spaced intervals around the perimeter or periphery, the moisture in the package can contact both sides of the film, thereby increasing the generation of gases. If the film is perforated as well, even greater contact can be had.

[0023] The inventive method and inventive packaging 1) promotes food safety; 2) prevents cross-contamination; 3) extends shelf life; and 4) enhances presentation. All materials used in the method and package of the present invention are GRAS and meet FDA and USDA requirements for direct food contact.

[0024] As previously noted, the present invention, both the method and the package, would apply to all modified-atmosphere packaging applications, e.g., meat, poultry, seafood, produce (fruits/vegetables) and flowers, and such like foods and articles. The invention enables fresh seafood to be packaged at a processor and shipped to the market, case-ready, and made available in stores alongside case-ready meat (steaks, pork chops etc.) and poultry (whole bird and pieces). Further, the invention will enable a better modified-atmosphere packaging of meats, poultry, flowers, vegetables, fruits and any other perishable commodity.

[0025] Although the invention has been shown and described with respect to a preferred embodiment and alternatives therefore, nevertheless changes and modification can be made. Such changes and modifications as will be evident to those skilled in the art from a knowledge of this disclosure and its teachings are deemed to fall within the purview of the invention as claimed. 

What is claimed is:
 1. A method of packaging a perishable item comprising the steps of placing the perishable item in the interior of a liquid tight container; and generating CO₂ and ClO₂ gases within the liquid tight container.
 2. The method of packaging according to claim 1 wherein the container is also gas tight.
 3. The method of packaging according to claim 1 wherein the container allows moisture vapor to pass through to the interior.
 4. The method of packaging according to claim 1 wherein the generation of gases is effected through activation by moisture vapor present in the interior of the container.
 5. The method of packaging according to claim 1 wherein the generation of gases is effected by gas generating ingredients dispersed in a portion of the container.
 6. The method of packaging according to claim 1 wherein the generation of gases is effected by gas generating ingredients present in a pad located in the container.
 7. The method of packaging according to claim 1 wherein the generation of gases is effected by gas generating ingredients dispersed in a coating located within the container.
 8. The method of packaging according to claim 1 wherein the container is a bag.
 9. The method of packaging according to claim 1 wherein the container is a tray.
 10. The method of packaging according to claim 1 wherein the container is a pouch
 11. The method delivering CO₂ and ClO₂ to an object comprising the steps of incorporating CO₂ and ClO₂ gas generating ingredients when subjected to moisture vapor into a patch attachable to an object.
 12. A method of packaging a perishable item comprising the steps of placing the perishable Item in a liquid and gas tight container having an opening located above the perishable item; and sealing the container opening with a liquid tight film of material permeable to gases with the film containing ingredients that will produce CO₂ and ClO₂ when contacted by moisture vapor.
 13. A method of packaging according to claim 12 wherein the film material constitutes a laminate of a top film a bottom film and a layer of adhesive binding said films together, with the ingredients being dispersed in the adhesive.
 14. A method of packaging according to claim 13 wherein the top film is characterized as having (1) a high moisture vapor transmission rate and (2) a low gas transmission rate, and the bottom film is characterized by having (1) a low moisture vapor transmission rate and (2) a high gas transmission rate.
 15. A package comprising, a liquid and gas tight container having an opening located in an upper portion; a perishable item located in the container below the opening; and a liquid tight film of material permeable to gases sealing said opening with the film containing ingredients that will produce CO₂ and ClO₂ when contacted by moisture vapor.
 16. A package according to claim 15 wherein the film material constitutes a laminate of a top film a bottom film and a layer of adhesive binding said films together, with the ingredients being dispersed in the adhesive.
 17. A package according to claim 16 wherein the top film is characterized as having (1) a high moisture vapor transmission rate and (2) a low gas transmission rate, and the bottom film is characterized by having (1) a low moisture vapor transmission rate and (2) a high gas transmission rate.
 18. A package according to claim 15 wherein the perishable item is selected from the class consisting of meats, poultry, flowers, vegetables, fruits, fish and seafood.
 19. A package according to claim 18 wherein the perishable item is fish.
 20. A package according to claim 18 wherein the perishable item is seafood. 